OK, I'm impressed!
I've written about and taught Python for almost 20 years. I never realized
`in` was a chained comparison. I'm pretty sure I've never seen it used
that way "in the wild." I also never tried using `is` in a chained way
until just now.
That said, there are at least three things perverse about the examples
below, and they should *definitely* never be used in real code.
This is vaguely plausible (for variable defined in some more interesting
way where the substring relation is not so obvious; say content read from
files):
>>> a = "a"
>>> b = "abc"
>>> c = "abcde"
>>> a in b in c
True
On Tue, Feb 28, 2017 at 6:56 PM, 语言破碎处 <mlet_it_...@126.com> wrote:
> I'm bited once:
> >>> '' in {} == False
> False
> >>> ('' in {}) == False
> True
>
> # '' in {} == False ==>> ('' in {}) and ({} == False) ==>> False!
>
> I think only compare operations should be chained.
>
>
>
>
>
>
>
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